NUCLEATION STUDIES OF THIN DIAMOND FILMS ON MODEL SUBSTRATES

Thin diamond films have been grown by hot filament chemical vapor depo sition (CVD) on untreated, diamond powder scratched and d.c.-bias pret reated Si(111), SiO2 and graphite substrates. The deposits were charac terized using X-ray photoelectron spectroscopy, scanning Auger micropr obe and scanning electron microscopy. The increased surface oxide thic kness due to scratching has no influence on the nucelation of diamond films since SiO2 films of known thickness have been found to be reduce d under growth conditions. Positive d.c.-bias pretreatment leads to an increased number density of nuclei which can be further increased by permanent biasing throughout the deposition. The pretreatment causes i ntermediate deposition of turbostratic carbon which promotes nucleatio n of diamond. The increased number density of nuclei is discussed in r elation to deposition of diamond on various forms of graphite.